Patent GB-890154-A (GB)
Title: Improvements in relating to friction clutches
IPC: F16D13/50
Filed: 1958-07-14
Abstract: 890,154. Friction clutches; securing together clutch elements; gearing for stopping and starting machinery. FRANCAISE DU FERODO S.A. July 14, 1958 [July 12, 1957], No. 22445/58. Class 80 (2). [Also in Group XXV] A friction clutch having a driven disc 12 clamped between a driving engine flywheel 10 and a presser plate 16 has the presser plate moved axially for clutch engagement against the bias of springs 46 by levers 58 pivoted at 59 upon a support 25, tangentially arranged leaf springs 27, Fig. 2, 3, connecting the lever support 25 to a clutch cover 17 fast with the flywheel but being flexed only when an externally threaded ring 22 is turned to adjust the clutch and compensate for wear of the driven disc friction linings, and additional tangentially arranged leaf springs 28 connecting the lever support 25 to the presser plate 16 but being flexed only by engaging and disengaging movements of the presser plate. The spring leaves 27 are connected by bolts 29 to the presser plate 17 and by bolts 30 to the lever support 25. The bolts 30 also connect the ends of the spring leaves 28 to the lever support 25, bolts 31 securing the remote ends of the leaves 28 to the presser plate 16. Cups 38 on the bolts 30, 31 lie freely within holes 39 in the clutch cover-plate 17, so that in the event of breakage of the leaf springs 27, 28, the clutch parts are maintained in correct alignment, the cups then engaging their associated holes. The wear-adjusting ring 22 has an inner peripheral groove 43 engaged by washers 42, Fig. 4, carried by bolts 44 in the lever support 25. Turning the ring 22 moves it axially within the clutch cover 17 and, since it abuts the lever support 25 at 24, moves the latter to take-up wear of the friction linings in the clutch. The wear-adjusting ring 22 is locked in position by a catch 74 engaging grooves 23 thereon and secured to the clutch cover 17 by a bolt 76. The clutch levers 58 pivoted upon the support 25 are also pivoted on levers 64 in turn pivotally connected to an axially slidable sleeve 65 actuated through a thrust bearing 67 by a clutch control fork 69. The levers 58, 64 form an over-centre toggle arrangement. Noses 60 on the levers 58 engage tangentially arranged leaf springs 50, Fig. 5, mounted by cut-away studs 52 on the presser plate 16 and held in pre-stressed condition by lugs 56 secured to the presser plate by bolts 57. Shims 61, 62 on the levers 58 and the engaged surfaces of the leaf springs 50 allow the working positions of the clutch throw-out levers to be adjusted so that they are all effective simultaneously. In the clutch-engaged position shown, the toggle links 58, 64 are in their overcentre position, and maintain clutch engagement. By operation of the control fork 69, the sleeve 65 is moved axially to the right of Fig. 1, and springs 46 become effective to withdraw the presser plate 16 from engagement with the driven clutch disc 12. As the clutch fork 69 completes its movement, a non-rotary friction surface 70 carried by the outer race of the thrust bearing 67 is brought into engagement with a brake disc. 71 fast upon the clutchdriven shaft 11. Inclined passages may be provided around the periphery 40 of the presser plate 16 to give a cooling effect.